The present invention relates to apparatus and methods of splicing two belt ends and particularly to such apparatus and methods for heat bonding of the two ends to form an endless belt.
Endless belts have innumerable uses in industry. Many such belts are constructed of a material having a woven fabric base coated on one or both sides with a thermoplastic material such as polyvinyl chloride (PVC) or polyurethane, a predetermined length of such material being joined at its ends to produce the desired endless belt. Conventionally, this joinder of belt ends is performed by cutting the respective belt ends to provide in the edges thereof respective pluralities of corresponding V-shaped teeth, thereby to provide a substantially greater belt end surface area for bonding than is provided by a transversely cut belt end; applying to the respective sets of teeth liquid PVC or another appropriate liquid thermoplastic bonding resin; abutting the belt ends in meshing juxtaposed relation; and applying heat to the joined belt ends to effect the bonding thereof by the liquid thermoplastic resin.
While this belt splicing operation produces belts of satisfactory quality and utility, there exist several disadvantages in this state of the art. First, the resultant belt produced is normally substantially weaker at the splice than along the remaining length of the belt which reduces the strength and useful life of the belt as a whole. The use of additional PVC or another thermoplastic resin at the splice additionally adds to the cost and labor of splicing belts. Further, the apparatus presently available for performing the splicing operation is relatively large and time and energy consuming in heating to the necessary temperature for splicing operation. As a result, practically usable apparatus is not available for the construction or repair of spliced belts at their location of use. Accordingly, the initial construction of endless belts must be performed at a location remote from the intended location of use which may create problems in the proper desired dimensioning of the belts and, further, any such belts failing in use, if they are to be repaired, must be returned therefor to the manufacturer.
In contrast, the present invention provides an apparatus and method for forming uniquely stronger splices of belt ends in substantially shorter time and with substantially reduced energy consumption than conventional apparatus and methods, without requiring the application of any additional PVC or another thermoplastic resin.